ES2301103T3 - AMORTIGUATION DEVICE FOR FURNITURE WITH A COMPENSATION SYSTEM FOR VOLUME CHANGES. - Google Patents

Abstract

A damping device (100), in particular for damping impacts of mobile parts in pieces of furniture, comprises: a casing (1) wherein is defined an inner chamber containing a viscous fluid and substantially closed at one end through a cap (2); a piston (3) slidably mounted in the inner chamber; a stem (4) having a first end (4a) associated with the piston (3) and a second end (4b) projecting from the inner chamber. The damping device (100) is characterised in that the cap (2) comprises at least one floating gasket (28) slidably mounted in a cavity (24) defined in the cap (2), said floating gasket (28) defining a region with variable volume in the cavity (24) suitable for receiving the viscous fluid displaced into the inner chamber by the stem (4) during the movements of the piston (3). The cavity (24) defined in the cap (2) and the floating gasket (28) slidably mounted in it define a system for compensating the variation in volume available in the inner chamber to receive the viscous fluid, due to the insertion/removal of the stem (4).

Description

Damping device for furniture with a compensation system for volume changes.

The present invention relates to a damping device, in particular a device damping to cushion impacts of moving parts of furniture.

The invention also relates to a piece of furniture that It comprises said damping device.

In the field of furniture of various types and for different uses consisting of mobile departments, such as sliding doors or drawers, the use of some is known damping devices that cushion the impacts of said moving parts when they come in contact with the fixed structure of the respective furniture. These impacts, besides being unpleasant for users, they can effectively compromise the long-term furniture functionality.

A type of damping device usually used for the exposed purposes is constituted by linear, composite hydraulic shock absorbers essentially by a piston slidably mounted within a housing that defines an inner chamber that contains a fluid viscous, responsible for the damping effect. The piston defines two zones of variable volume inside the internal chamber: when the force of an impact discharge on a stem associated with the piston, the viscous fluid is forced to pass from a first zone in which the pressure is increased to a second zone of low pressure at which the fluid is collected. When the push exerted on the rod stops, a spring reattaches the piston and the rod and fluid returns to the first zone, so that the Damper is ready for another operating cycle.

Although the damping devices of this type are also known in other technical fields, the versions used in the furniture industry must meet requirements specific operations, as well as strict profitability demands and compactness that are essential in this field, determining its structural and functional characteristics.

In particular, in damping devices of furniture of the type described above there is a requirement of that the volume of the inner chamber is completely filled with the viscous fluid to avoid noise during operation and to optimize the damping action. While satisfying this requirement should be considered that, when the stem is inserted inside the inner chamber due to an impact, the volume available for viscous fluid inside the inner chamber is reduces due to the volume of the stem itself and then increases again when the stem comes out during the race of repositioning Consequently, they have developed certain damping devices that are equipped with a system to compensate for the volume of displaced viscous fluid by the rod during piston movements. In general, said damping devices comprise a cavity appropriate variable volume in fluid communication with the internal chamber, which substantially acts as a lung for the volume change produced inside the inner chamber when the stem is inserted / removed.

In known damping devices, the volume change within the compensation system cavity of volumes is usually achieved by placing inside the cavity a spongy body with closed alveoli that contain a fluid compressible, typically air, which can be compressed, increasing the volume of the cavity, under the effect of the thrust of the viscous fluid.

Furniture damping devices equipped with a volume compensation system of the type described above are disclosed, for example, in the documents US 2003/0075845 A1 and US 2002/0010977 A1.

Said damping devices, although substantially appropriate to meet the requirement previously exposed, they present some inconveniences.

A first drawback is connected to the overpressure (compared to atmospheric pressure) that occurs in the inner chamber after compression of the spongy body to the volume compensation of the viscous liquid displaced by the insertion of the stem into the inner chamber. Bliss overpressure determines the additional unwanted thrust on the rod and on the piston which tends to push the rod out of the inner chamber and could therefore prevent a moving part will close properly in contact with the damping device

A second inconvenience is connected to the presence of a compressible fluid, such as air, inside of the alveoli of the spongy body. The break of one or more alveoli, for example, by wear, may compromise the correct operation of the damping device due to the formation of compressible fluid dispersions in the fluid viscous.

The purpose of the present invention is provide a damping device that is capable of overcome the drawbacks of the prior art and make it constructively simpler and more compact.

According to a first aspect of it, the The present invention, therefore, concerns a device for cushioning, in particular to cushion parts impacts Furniture mobiles, comprising:

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a housing in which an inner chamber is defined that contains a viscous fluid and that is substantially closed at its end opened by a lid;

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a piston slidably mounted inside the chamber internal;

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a rod that has a first end associated with the piston and a second end that is projected from the internal chamber through said lid,

characterized in that said lid it comprises at least one sliding joint mounted in sliding form within a defined cavity in the lid, said joint defining floating within said cavity an area with variable volume suitable for receiving the viscous fluid displaced within said inner chamber by said rod during said movements piston.

The defined cavity inside the lid and the gasket float mounted slidably within that define a system to compensate for the volume change available in the camera inside to receive the viscous fluid, hereinafter defined in the present memory as "useful volume", said change being due to the insertion / removal of the stem. The compensation takes place from effectively thanks to the sliding ability of the joint floating inside the cavity defined inside the lid, being controlled said sliding by the flowing viscous fluid from the inner chamber of the damping device to said cavity and vice versa.

During the driving stroke of the piston, that is, the run in which impact cushioning takes place, the Useful volume of the inner chamber of the damping device It is reduced due to the insertion of the stem and viscous fluid displaced accordingly flows into the defined cavity inside the lid. This causes the floating joint to slide to increase the volume of the area with variable volume defined by the floating joint located inside the mentioned cavity. During the subsequent piston replacement stroke, that is, the stroke in which the piston and rod are reintroduced in its initial position to carry out another operational cycle, the stem comes out of the inner chamber of the damping device with an increase in useful volume, which can again be filled by the viscous fluid temporarily accumulated previously in the variable volume zone, defined by the floating joint. During the flow of viscous fluid from the defined cavity within the cover towards the inner chamber of the damping device, there is also a sliding of the floating joint in the opposite direction to the previous direction and with the intensity necessary to reduce the volume of the volume zone variable.

Advantageously, the compensation system of volumes described above avoids the use of oppressive bodies,  such as spongy bodies that incorporate air, to Develop volume compensation. The device of damping of the invention enables the substantial elimination of the above described inconveniences with reference to technical damping devices previous and has, in comparison with them, a global structure simpler, with the consequent cost savings of manufacturing.

An additional structural simplification of the damping device of the invention is due to the advantageous possibility of using a floating joint for both the compensation of volumes as a sealing element for which reason it is not it is necessary to supply additional cover gaskets to secure the hermetic closure of the external chamber.

Likewise, the compensation system of volumes are advantageously defined inside the lid, for substantially limit the overall dimensions of the device damping of the invention.

Preferred features of the device damping according to the invention are defined in the attached claims 2 to 9, the content of which is incorporated totally herein by reference.

According to a second aspect of it, the current invention refers to a piece of furniture comprising a device  of damping of the type mentioned above.

Of course, the advantageous features outlined above with reference to the damping device of the present invention define many other features advantageous of the furniture within which the device can be mounted of damping, therefore being said structural furniture and functionally simpler and less expensive.

Additional features and advantages of the invention will become more clearly apparent from the subsequent description of some of its embodiments Preferred, set forth herein below, with indicative and non-limiting purposes, with reference to the drawings attached. In these drawings:

- Figure 1 is a perspective view in neat exploded view of a damping device according to the invention;

- Figure 2 is a side view of a housing of a damping device of figure 1;

- Figure 3 is a sectional view longitudinal taken along line A-A of the housing of figure 2;

- Figure 4 is a side view of a cover of the damping device of figure 1;

- Figures 4a, 4b are respectively a front view and a rear view of the lid of figure 4;

- Figure 5 is a sectional view longitudinal taken along line B-B of the cover of figure 4;

- Figure 6 is a side view of a piston of the damping device of figure 1;

- Figures 6a, 6b are respectively a front view and a rear view of the piston of figure 6;

- Figure 7 is a sectional view longitudinal taken along the line C-C- of the piston of figure 6;

- Figure 8 is a side view of the piston of Figure 6 functionally associated with a floating shutter in a  first operational position;

- Figure 8a is a sectional view longitudinal taken along the D-D line of the piston of figure 8;

- Figure 9 is a side view of the piston of Figure 6 operatively associated with a floating shutter in A second operational position.

- Figure 9a is a sectional view longitudinal taken along the E-E line of piston of figure 9;

- Figure 10 is a side view of the damping device of figure 1 in a first operational configuration;

- Figure 10a is a sectional view longitudinal taken along the F-F line of damping device of figure 10;

- Figure 11 is a side view of the damping device of figure 1 in a second operational configuration;

- Figure 11a is a sectional view. longitudinal taken along the G-G line of the damping device of figure 11.

In said figures, a device of cushioning according to the invention is globally designated with reference numeral 100.

The damping device 100 (fig. 1) essentially comprises a housing 1 within which it is defined an internal chamber 12, a cover 2 that substantially close the inner chamber 12 producing a tight seal with the internal surface of the housing 1, a piston 3 mounted so slidable inside the inner chamber 12, an associated rod 4 with piston 3 and a replacement element 6.

The housing 1 (figs. 2 and 3) is preferably cylindrical and has a first closed end 1a and a second longitudinal end 1b open to enable the insertion of the piston 3 and other components located within the same housing 1. After assembly of said components, the cover 2 is applied at the longitudinal end 1b. Inside the housing 1, at the level of the longitudinal end 1a a pin 11 is formed which defines a contact for the
piston 3.

The internal chamber 12 defined by the housing 1 has an appropriate volume V to receive the components mentioned above and containing a viscous fluid responsible for the damping action. Said viscous fluid is preferably a silicone based fluid. Of the usual type known by experts in the field and available in the market.

The piston 3 is slidably mounted inside the internal chamber 12 and defines within it two zones Z_ {1}, Z_ {2} of variable volume in fluid communication each other in at least one conduit 31 defined within the piston 3 and in a hollow space 32 defined between the outer surface of the piston 3 and the inner surface of the housing 1.

A floating shutter 5, preferably of spherical shape is operatively associated with piston 3 to close the conductor 31 during the driving stroke of the piston 3 and to open the duct 31 during the piston replacement stroke 3.

The piston 3 (figs. 6, 6a, 6b, 7) comprises essentially a central body 33 and a seat 34 for the shutter  floating 5, preferably at least partially defined by the projections 35 projecting axially from the central body 33. Inside the seat 34 the floating shutter 5 is free for move between a first operational position in which you open the duct 31 (figs. 8, 8a and 10a) and a second operative position in which closes the duct 31 (figs. 9, 9a and 11a) according to the movement of the piston 3 inside the inner chamber 12.

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Preferably, the central body 33 comprises a first portion 33a having a wide cross section and a second portion 33b, which extends axially from the first portion 33a on the side opposite seat 34. The second portion 33b defines with the internal surface of the housing 1 at least one reception area 38 of the viscous fluid in fluid communication with conduit 31. The first portion 33a preferably has a substantially cylindrical shape and the second portion 33b has preferably a substantially prismatic shape, even more preferably parallelepipedic or cubic. The second portion 33b preferably it comprises at least two edges diametrically opposites 36 that extend radially beyond the first portion 33a. The corners 36, preferably chamfered, are appropriate to cooperate with the inner wall of the housing 1 to guide the piston stroke 3.

In the second portion 33b a blind hole is also defined in an axial position to receive the first end 4a of the stem 4, for example by forced adjustment. A second end 4b of the rod projects axially from the internal chamber 12 in cover 2 inside the rest of the configuration of the damping device 100 (Figs. 10, 10a). Preferably, the second end 4b of the second rod is associated with a pushrod 41, which is preferably equipped with a contact element 42 made of rubber for cushion the noise of impacts.

Preferably, the conduit 31 defined in the piston 3 comprises at least a substantially axial portion 31a in the first portion 33a of the central body 33 and at least one substantially radial portion 31b in the second portion 33b of the central body 33. In the case where the second portion 33b is prismatic, at least a substantially radial portion 31b of the conductor 31 extends substantially perpendicular to a lateral face of the second surface 33b of the central body 33.

In the embodiment illustrated in the present report (see in particular Figs. 7, 8a, 9a), the substantially radial portion 31b of conduit 31 extends between two diametrically opposite side faces of portion 33b of the central body 33 and is in fluid communication with two zones of reception 38 of the viscous fluid, which are defined in the opposite sides of portion 33b between the side faces above and the inner surface of the housing 1. The conduit 31, therefore, defines through the piston 3 a substantially T-shaped path destined for viscous fluid.

Cap 2 (Figs. 4, 4a, 4b and 5) preferably it consists of a substantially cylindrical hollow body, or in Any case has a cross section and dimensions external such that they allow it to be coaxially mounted inside of the housing 1 at the end 1b for at least a portion of the cover 2 and, preferably, for its entire longitudinal extension, as illustrated in Figures 10a and 11a.

According to the invention, the cover 2 comprises at least one floating joint 28 slidably mounted inside of a cavity 24 defined in the cover 2. Floating joint 28 defines an area with a variable volume Z 3 within cavity 24, appropriate to reversibly receive viscous fluid displaced inside the inner chamber 12 by the stem 4 during piston movements 3.

Preferably, the cover 2 also comprises a ring partition 26 (visible in Figs. 1, 10a and 11a) appropriate to axially divide the cavity 24 of the inner chamber 12. The presence of the annular partition 26 is advantageous for defining a contact for the floating joint 28.

Preferably, the cavity 24 is in fluid communication with internal chamber 12 at the level of a hole 27 defined in the annular partition 26 and arranged to enable sliding coupling with rod 4 with a predetermined radial strike 29. Advantageously, said radial strike 29 enables the internal chamber 12 to be located in fluid communication with cavity 24 in a simple and compact

Preferably, the annular partition 26 is removably associated with the cover 2, to enable the floating joint 28 is easily mounted inside the cavity 24.

On the opposite side of the annular partition 26 the cavity 24 is axially defined by a transverse wall 21 defined inside the lid 2 and having a hole 22, substantially coaxial with hole 27, for the passage of the stem 4, in this case with a minimum radial strike just for the dimensional tolerances.

The cavity 24 and the floating joint 28 advantageously they define a system to compensate for the variation of the useful volume produced in internal chamber 12 due to the insertion / removal of rod 4, as best illustrated in the present memory later with reference to the operation of the damping device 100.

In the preferred embodiment of the invention illustrated herein, the floating joint 28 is a double seal joint, also known to experts in the Matter with the term X-joint or sleeve joint, arranged to provide a tight seal on the side walls of the cavity 24 and on the rod 4. The possibility of producing a tight seal also on the stem 4 through the joint floating 28 and, therefore, of substantially insulating Hermetic inner chamber 12 and cavity 24 to the side exterior, advantageously enables the structure of the 100 damping device is simplified, since it can avoid using an additional gasket specifically arranged for this purpose

The damping device 100 has the precise size so that the cross sectional ratio of the cavity 24 with respect to the cross section of the stem 4 preferably range between about 5 and about 30, more preferably between about 10 and about 20. This allows to achieve volume compensation with a minimum axial sliding of the floating joint 28 inside the cavity 24 and therefore allows the axial extension of the cavity 24 and the overall dimensions of the device 100 damping are advantageously limited.

As illustrated in Figure 5, cover 2 it also preferably comprises a seat 23 adapted for receiving the push rod 41 of the stem 4 substantially of complete form in the operational configuration in which the piston 3 It is at the open end of its motor race (Figs. 11, 11a). With in order to avoid accidental detachment of the rod from thrust 41 relative to rod 4, at least one longitudinal groove 25 which has an axially outer end located at a distance default of the outer edge of the cavity 23 is preferably defined on the internal surface of the cavity 23, said groove being adapted to receive slidably at least one projection 43 extending laterally from the push rod 41.

The damping device 100 comprises likewise a conventional replacement element 6, for example a coil spring, suitable for supplying the required force to replace piston 3 and rod 4. In the embodiment preferred here illustrated, the replacement element 6 is housed inside the housing 1 and is operatively arranged between the longitudinal end 1a of the housing 1 and the piston 3.

With particular reference to Figures 10a and 11a below will describe the operation of the device of damping 100. Figure 10a shows the device for 100 damping in a first operational standby configuration, when external forces do not act on the device. In this operational configuration, the reset element 6 maintains the piston 3 pressed against the annular partition 26 of the cover 2 and the push rod 41 associated with the rod 4 projects from the housing 1 in a state of maximum extension from the seat respective 23 defined in cover 2.

Under an external force F, due for example to an impact against the push rod 41 after the closure of a movable part of a piece of furniture, the piston 3 moves in the direction of arrow A, developing the motor race. The displacement of piston 3 determines within the internal chamber 12 a reduction of zone volume Z_ {1} and an increase in zone volume Z_ {2}. The movement of piston 3 combined with the increase in pressure in zone Z_ {1} disposes and maintains shutter 5 in its second operative position, in which the 31st portion of the conduit 31, preventing the passage of viscous fluid. In this situation, the only step available for the viscous step towards the zone Z_ {2} consists of the hollow space 32 for which reason the resistance against the movement of the piston 3 and the effect of Damping is at its peak.

During the driving stroke of piston 3, the useful volume available for the viscous fluid existing in the internal chamber 12 is reduced due to the progressive insertion of the stem 4. Said volume reduction is compensated by the volume increase of the zone Z_ {3} existing in the cavity 24 of the cover 2, which is made possible by sliding the floating joint 28 inside the cavity 24 caused by the thrust of the viscous fluid itself. The viscous fluid displaced by the stem 4 can flow from the internal chamber 12 inside the cavity 24 thanks to the radial clearance 29 between the hole 27 of the annular partition 26 and the rod 4 slidably mounted through that one.

The driving stroke of piston 3 ends when the floating shutter 5 is placed in contact against the stud 11 of the housing 1 and pushrod 42 is substantially housed in full form inside seat 23 of the cover 2. The device 100 damping is like this in a second configuration operational, represented in Figure 11a and remains in said configuration until the external force F is applied, for example  as long as the movable part of a piece of furniture remains closed.

When the external force F is suppressed, the replacement element 6, compressed during the driving race, determines the replacement stroke, in which the piston 3 is shifts in the direction of arrow B. The displacement of the piston 3 determines in the internal chamber 12 a volume reduction of zone Z_ {2} and an increase in volume of zone Z_ {1}. The movement of piston 3, combined with the increase in pressure in zone Z_ {2}, causes shutter 5 to move away from the piston 3, and place the shutter 5 in its first operating position, in which the conduit 31 of the piston 3 opens. In this situation, the viscous fluid can flow from zone Z2 to zone Z_ {1} both through the hollow space 32 and through the duct 31. The resistance against the movement of the piston 3 and the required replacement force are therefore substantially low.

During the replacement stroke of piston 3, the useful volume available for the viscous fluid existing in the internal chamber 12 is again increased thanks to the withdrawal progressive stem 4, and viscous fluid previously housed temporarily in cavity 24 of lid 2, you can again flow inside the inner chamber 12. This flow causes that the floating gasket 28 slide towards the annular partition 26 with the consequent reduction in volume of the zone Z3.

The reset race ends when the piston 3 is placed in contact against the annular partition 26 of the cover 2 and the damping device 100 is again in the First operational configuration.

The damping device 100 has a use preferred but not exclusive in furniture to cushion the impacts of moving parts that come into contact with a fixed structure of the respective furniture. Therefore, the device 100 damping can be installed inside a piece of furniture (not illustrated in the figures), comprising a fixed structure, to the which the housing 1 of the damping device 100 is fixed,  a moving part, for example a door or a sliding drawer, the which during closing are in contact with the device 100 damping.

Claims (11)

1. Damping device (100), in particular for impacts of moving parts of furniture, which understands:

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a housing (1) in which an internal chamber (12) is defined that contains a viscous and substantially closed fluid at its opposite end by a cover (2);

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a piston (3) slidably mounted inside said chamber internal (12);

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a stem (4) having a first end (4a) associated with said piston (3) and a second end (4b) projecting from said internal chamber (12) through said cover,

characterized in that said cover (2) comprises at least one floating joint (28) slidably mounted within a cavity (24) defined in said cover (2), said floating joint (28) defining within said cavity (24) a zone (Z 3) with an appropriate variable volume to receive the viscous fluid displaced inside said internal chamber (12) by said rod (4) during the movements of said piston (3). 2. Damping device (100) according with claim 1, wherein said cover (2) comprises a annular partition (26) suitable for axially dividing said cavity (24) of said internal chamber (12). 3. Damping device (100) according with claim 2, wherein said cavity (24) is in fluid communication with said internal chamber (12) in a hole (27) defined in said annular partition (26) and arranged to receive said rod (4) with a predetermined radial clearance. 4. Damping device (100) according with claim 2, wherein said annular partition (26) is removably associated with said cover (2). 5. Damping device (100) according with any one of the preceding claims, wherein said floating joint (28) is a double seal joint arranged to provide a tight seal on said rod (4) and on said side walls of said cavity (24). 6. Damping device (100) according with any one of the preceding claims, wherein the relationship of the cross section of said cavity (24) with with respect to the cross section of said rod (4) it ranges from about 5 and about 30. 7. Damping device (100) according with claim 6, wherein the relationship of the section transverse of said cavity (24) with respect to the section transverse of said rod (4) ranges between approximately 10 and approximately 20. 8. Damping device (100) according with any one of the preceding claims, wherein said cover (2) comprises a seat (23) adapted to receive substantially completely a push rod (41) associated with said second end (4b) of said rod (4). 9. Damping device (100) according with claim 8, wherein said seat (23) comprises the minus a longitudinal groove (25) adapted to receive Sliding at least one projection (43) that extends laterally from said pushrod (41). 10. Damping device (100) of according to any one of the preceding claims that comprises a replacement element (6) suitable for providing a replacement force for said piston (3), said being replacement element (6) housed within said internal chamber (12). 11. Furniture comprising a device for damping (100) according to any one of the preceding claims.